The invention relates to a rotary snow blower plow with a plow worm which delivers the snow and a fan blower which throws the delivered snow. Furthermore the invention relates to a means with one such rotary snow blower plow.
1. Prior Art
Rotary snow blower plows are used to clear larger amounts of snow. On the one hand, they have a plow worm and on the other a fan blower. The plow worm breaks up the snow and delivers it to the fan blower, from which it is specifically thrown away via a chimney.
Rotary snow blower plows are used not only in the municipal domain (roads, parking lots, etc.), but also to prepare ski and snowboard courses. In any case the user is interested in the rotary snow blower plow having efficiency as high as possible. If there is already a utility vehicle, with its (often limited) power a working speed as high as possible is to be reached. If a new utility vehicle is procured, the lower power consumption of the rotary snow blower plow has the advantage that savings are possible in the power of the utility vehicle.
Snowboarding is very popular, mainly among the young. Demanding snowboarders however are not satisfied with riding on ordinary ski courses, but look for a challenge in specially prepared, channel-like snow vales which are called half pipes. One such snow vale in cross section has a flat middle part and two arc-shaped side walls. The radius of the side walls is in the range of 2.0-3.5 m.
For mechanical production and maintenance of these snow vales only one device is available on the market which can be attached to a conventional snow smoother. It consists essentially of a bogie truck and a curved plough which projects laterally from the roadway. The (often slightly compacted or hardened) snow is broken up with the indicated curved plow and conveyed to the outside with a scoop chain. The final shape of the side wall is produced with a correspondingly bent blade edge.
Specifically in the preparation of a half pipe course it must be considered that it must be cut in a slope with considerable steepness (typically 14xc2x0 to 22xc2x0). In spite of high weight, in the known device there is the problem that it can drift from the correct position (i.e, from the direction of travel) in the case of heavy or hard snow.
2. Description of the Invention
The object of the invention is to devise a rotary snow blower plow of the initially mentioned type which is characterized by increased efficiency.
According to the invention, the fan blower is located on one line (i.e. on the same geometrical axis) with the plow worm.
In contrast to the convention rotary snow blower plows, in the invention the flow of snow need not be deflected by 90xc2x0 to supply the fan blower. This benefits the efficiency and the power consumed. The invention is especially suitable for side wall clearing and preparation of half pipe courses.
Especially good efficiency can be achieved by the fact that the fan blower and the plow worm are attached on a common shaft. The fan blower and plow worm are therefore rigidly coupled to one another to rotate. The drive can be structurally made relatively simple as a result.
Preferably the device is equipped with a hydraulic drive. This is supplied by the utility vehicle. Instead of a hydraulic drive a mechanical one can also be used.
Preferably the plow worm and fan blower run with different speed. For this purpose there can be gearing which produces a certain stepping-down. The lower rotation speed of the plow worm is advantageous for optimization of efficiency. At the same time, it can be desirable specifically in the municipal domain (for example in the clearing of side walls) for reasons of safety engineering if the plow worm runs comparatively slowly (the peripheral speed of the fan blower should not fall below a stipulated minimum value). The step-down ratio is at least 1:2, preferably roughly 1:4.
The rotary snow blower plow as claimed in the invention is preferably used as a component of a device for preparing half pipe courses. One such device has not only an individual plow worm, but a plurality of plow elements which are located on an arc (according to the side wall to be prepared). The plow elements themselves have barrel-shaped envelope curves in order to be able to plow a continuous arc.
The device comprises a blade edge and a curved plow which has been placed in advance of this edge (in the direction of travel). On the bottom of the curved plow is the rotary snow blower plow. The curved plow itself and its drive are made such that the snow to be removed is driven downward or inward to the snow blower.
Viewed in terms of the process, the snow is first broken down by the curved plow and delivered downward and inward and then from there it is conveyed away in the snow blower in a direction which is freely selectable according to requirements of individual case.
In contrast to the known process, in the invention the snow is moved, not directly to the outside, but first to the inside (where it actually cannot remain). From this location the snow however at this point is thrown, carefully directed. The direction can be rather freely chosen by the user. In this way it becomes possible to specifically fill holes when maintaining the snow vale or to raise the side wall.
Another advantage of the invention consists in that the side wall can be made optionally steep. In particular, it is not a problem to prepare a wall with a vertical section on the upper end since the snow is not scooped directly over this section, but is always brought first downward to the snow blower.
According to one preferred embodiment the means as claimed in the invention is rigidly guided on the front side of a snow smoother. The driver thus has more precise control over the direction of travel. He notices immediately on the vehicle when the curved plow is trying to swing and can consequently countersteer.
If to the left and right of the vehicle one curved plow at a time is mounted, it is always possible to work from bottom to top (i.e. uphill). It is consequently unnecessary to turn the vehicle on the upper end of the half pipe (which is often a problem). Otherwise in this way the two side walls of the half pipe course can be simultaneously cut from the new snow. This process leads to largely symmetrical loading. The unwanted torques which try to turn the entire means out of the direction of travel are minimal.
The drive is for example a hydraulic motor which is connected in series to another hydraulic motor to drive the snow blower. The curved plow is formed for example by multiple plow worms.
In contrast to the prior art, the assembly as claimed in the invention does not require a scoop chain. In this respect it is a simple construction.
Advantageously the blade edge is located in a surface which is sloped to the vertical plane. The blade edge should form a curve which moves away farther and farther to the front as the height increases (i.e. from the vertical plane in the direction of travel). In steep terrain (when climbing) it is thus ensured that the snow masses slide easily to the inside toward the snow blower. Preferably the blade edge runs in a plane which is tilted by a maximum 30xc2x0 (especially by 10 to 25xc2x0) to the vertical.
The curved plow can be swivelled around an axis such that it can be placed to the inside above the snow blower for transport purposes. The swivel axis runs essentially in a horizontal plane (i.e. the plane parallel to the roadway). It can be slightly increased relative to the direction of travel in order to bring the center of gravity of the curved plow in the folded-in state nearer the vehicle.
The curved plow as claimed in the invention is preferably made as a separable assembly to an existing rotary snow blower plow. I.e. it can be mounted laterally to the side as required.
In contrast to the prior art, the curved plow as claimed in the invention does not require especially great inherent weight to keep to the track. It is rigidly connected to the motor vehicle and consequently has the corresponding guidance. Therefore the effort is made to build the separable assembly to be as light as possible. It has been shown that it is possible to make do with roughly one eighth of the inherent weight of the known device.
Other advantageous embodiments and feature combinations of the invention follow from the following detailed description and the totality of the patent claims.